Objective To investigate the correlation between immature granulocyte and CD34+ cells, mononuclear cells (MNC) in donor's peripheral blood by recombinant human granulocyte colony-stimulating factor (rhG-CSF). Methods The stem cell were mobilized by rhG-CSF 7.25-10 μg·kg-1·d-1 from 122 allo-PBSCT donors. Before and after mobilization, to test CD34+ cells of peripheral blood stem cell graft and number of MNC, immature granulocyte, CD34+ cell per patient' weight were calculated. Results White blood cell count and immature granulocyte gradually increased, and reached the peak on the frith day. There was a good relationship between increased immature granulocytes and increased CD34+ cells. The patients all achieved completed donor engraftment and achieved hematopoietic recovery. The chromosome, blood type and HLA type were transformed to be donor's type. Ph1 changed to be negative in CML patients. Conclusion rhG-CSF (7.25～10 μg·kg-1·d-1) had a good effect to mobilize PBSC. There was a good relationship between in-creased immature granulocytes and increased CD34+ cells after mobilization by rhG-CSF. The number of immature granulocytes can reflect indirectly the count of stem/progenitor, so the MNC and immature granulo-cytes can become a threshold of dosage standard.